HEI conversion Dodge ram truck coil

George,
I have this info from a very knowledgeable electrical engineer. Checking the pri resistance of an ign coil with a digital meter will give an accurate reading. But checking the sec resistance can lead to errors & an analogue DVM should be used. He did say the reason, but it escapes me...I think it has something to do with the magnetic field that is generated whilst measuring the resistance.